feat(rds): enhanced monitoring configuration at the cluster level (#3…

…2157)

### Issue # (if applicable)

None

### Reason for this change

AWS RDS now supports the configuration of advanced monitoring at the cluster level.

<https://aws.amazon.com/about-aws/whats-new/2024/09/amazon-rds-performance-insights-supports-aurora-cluster-level-configuration/?nc1=h_ls>

This feature is essential for creating limitless database cluster. (#32151)

### Description of changes

I added `enableClusterLevelEnhancedMonitoring` prop to `ClusterProps`.
If this prop enabled, `monitoringInterval` and `monitoringRole` is applied to not the instances but the cluster.

Enhanced monitoring configuration for the cluster and instances has some restrictions.
- When setting the `monitoringRoleArn` for both the cluster and instances, the values must be identical.
- When setting the `monitoringInterval` for both the cluster and instances, the values must be identical.
- When the `monitoringInterval` or `monitoringRoleArn` is set at the cluster level, enhanced monitoring will be enabled even if the same values are not specified for the instances.

Based on the above, I decided to add a flag (`enableClusterLevelEnhancedMonitoring`) to switch the application of `monitoringInterval` and `monitoringRole` between the instance level and the cluster level to avoid breaking changes to the existing props.


#### Verification Results Memo

The value of the Enhanced Monitoring configuration must be the same for both the cluster level and the instance level.

```ts
  "DatabaseB269D8BB": {
   "Type": "AWS::RDS::DBCluster",
   "Properties": {
    ...,
    "Engine": "aurora-postgresql",
    "EngineVersion": "16.1",
    "MonitoringInterval": 5,
    "MonitoringRoleArn": {
     "Fn::GetAtt": [
      "DatabaseMonitoringRoleForCluster91F5067E",
      "Arn"
     ]
    },
  },
  "DatabasewriterInstanceEBFCC003": {
   "Type": "AWS::RDS::DBInstance",
   "Properties": {
    ...,
    "DBClusterIdentifier": {
     "Ref": "DatabaseB269D8BB"
    },
    "Engine": "aurora-postgresql",
    "MonitoringInterval": 1,
    "MonitoringRoleArn": {
     "Fn::GetAtt": [
      "DatabaseMonitoringRole576991DA",
      "Arn"
     ]
    },
  }
```

```sh
           | Database/writerInstance (DatabasewriterInstanceEBFCC003) Resource handler returned message: "MonitoringInterval conflicts with cluster level parameter. (Service: Rds, Status Code: 400, Request ID: 7c9d9023-fe2a-4b39-a939-22cec3595041)" (RequestToken: bc3e18eb-2daa-4f25-c205-11f1ec70fc15, HandlerErrorCode: InvalidRequest)
```

The monitoring role arn must be the same for both cluster and instance level.

```yaml
 "DatabaseB269D8BB": {
   "Type": "AWS::RDS::DBCluster",
   "Properties": {
    ...,
    "Engine": "aurora-postgresql",
    "EngineVersion": "16.1",
    "MonitoringInterval": 5,
    "MonitoringRoleArn": {
     "Fn::GetAtt": [
      "DatabaseMonitoringRoleForCluster91F5067E",
      "Arn"
     ]
    },
  },
  "DatabasewriterInstanceEBFCC003": {
   "Type": "AWS::RDS::DBInstance",
   "Properties": {
    ...,
    "DBClusterIdentifier": {
     "Ref": "DatabaseB269D8BB"
    },
    "Engine": "aurora-postgresql",
    "MonitoringInterval": 5,
    "MonitoringRoleArn": {
     "Fn::GetAtt": [
      "DatabaseMonitoringRole576991DA",
      "Arn"
     ]
    },
  }
```

```sh
Resource handler returned message: "MonitoringRoleArn conflicts with cluster level parameter. (Service: Rds, Status Code: 400, Request ID: 761a867d-409e-4208-a08e-5591607d0ed0)" (RequestToken: fb691324-f37c-405d-e5bd-447911f7664f, HandlerErrorCode: InvalidRequest)
```

### Description of how you validated changes

Add both unit and integ tests

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*